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Topic: Magnavox 153B Hepplewhite Console (Read 2311 times)

This my first and so far, only vintage Hi-Fi unit. I found it on Craigslist priced at fifty dollars. It also had a FM converter in it's own housing. it had a ruined aftermarket turntable that was only fit for the trash bin. It appeared to have had some critters living in it at one time and fortunately that had only taken out 1 trimmer capacitor. I have recapped it, and found a replacement trimmer for the receiver's shortwave section. I had to get a capacitor checker to determine the value of caps not shown in the schematic nor layout. It has a nice clear amplifier and the radio is a very good performer with the 50 ft. antenna and ground rod I set up for it.

When I got the console, I found one of the speakers had a rough hole through the cone with a corresponding hole in the grille/cloth. I used a patch of the same weight paper with feathered edges to repair the cone. This made a relatively flexible noiseless repair. After that, I pulled the console receiver and replaced all the paper and electrolytic capacitors. A hint for those of you attempting this. you may find as I did the unit you have differs from the schematic and the color dots on the caps are so discolored, you can't read them. I purchased a capacitor tester to determine the actual value of the capacitor for replacement. With old caps, the dielectric strength is the value that suffers beyond that of the capacitance. One thing that helps with the electrolytic caps, I keep a industrial strength soldering gun to allow setting up chassis tie points, for connection of the filter caps in areas where they are used.

It's been interesting leafing through the old Magnavox catalogs. In the 1946 edition, I was surprised to see a picture of the 153B with Irene Dunne, Russel Crouse and Howard Lindsay seated around it. I had seen product placement ads with Paramount stars, but not Warner Brothers. The people in the picture were involved with the film Life With Father, which was released in 1947.

Well, I checked the antenna lead in for problems. It was unaffected, though I went ahead and put synthetic grease into the break out Where the ground is connected. I pulled the CR-198B receiver to check out the condition of the electrolytic filter caps as it seems as though the increased amount of 60 Hz noise could have been a sign of a failing filter cap. It was. I can't believe I actually missed replacing the #46 cap when I was doing the recap. I replaced it and the noise was reduced in the shortwave mode, but the severe noise remains in the broadcast mode, with WGST 640 being the only station that isn't covered with 60 Hz noise. The AF section is dead quiet.

I believe I have found the problem. There is so much RFI on my house wiring from all my modern conveniences, I was at a loss over how to subdue it. I decided on an ac line RFI filter. It substantially cut down the RFI and the grounded shielded coax antenna lead in brought it down yet further. I just tried the console without the filter inline. No difference with or without. Apparently it has failed. It was rated for 10 amps load max. I am ordering a 20 amp module.

About a year ago I did the old unplug each item in the house test and most of the RFI went away. I have a bushel basket of wall warts making noise around the house. I had almost forgot how bad it was til now. Also, the utility transformer was replaced with an aging light pole about a year and a half ago.

I had just assumed that wall-warts are just a little transformer, diodes, and filter caps. Are they switching supplies now? My house is pretty quiet on the AM band frequencies. Last night I was running two radios to listen to WSM in Nashville, ca. 700 miles away. One was a GE Superradio II and one was the old GE P-780. The older GE is running on batteries and the newer one on its AC supply. Things were acceptably quiet here.

I could get WSM about this time of evening before this failure. This old receiver is pretty sensitive to RFI. I had a LED night light that put up noise at different points all across the shortwave spread. all the other power supplies put up a lot of noise, to the exclusion of much of the AM band.

But is the noise WORSE now than before? If yes, then there's some other point of failure, not just a modern house full of RFI emitters. I've read accounts of interference caused by dirty insulators on the electric distribution system. That's usually worse when there's moisture in the air. Apparently the power companies know about the issue and will respond if you complain. Collinite makes a special wax for the insulators. But your complaint sounds like t was a sudden change. Odd.

I tried my solid state AM receiver this afternoon. It had horrible noise across the scale! It has never had this much. So I went through the ritual unplugging of each of the items in the house. When I got to the cable boxes' wall wart, I unplugged it from the box, the noise dropped by half. I unplugged it from the wall and all the noise dropped out. I have spent the afternoon grafting the coaxial power connector onto a grounded switching dc power supply and have it set up now. I am listening to a Fort Wayne Komets hockey game on WOWO. It had been hard to get it on a clear night, much less a overcast rainy night like tonight. The shortwave noise floor is substantially lowered and Radio China and Radio Havana came in mighty nicely.